Solar Cookers - Using Sunlight to Cook Your Food
Solar cookers, or solar ovens are devices which utilize the energy from the sun to cook or heat food. They can be purchased commercially for a nominal fee, or homemade using readily available materials from a typical household. Solar ovens can be used to cook the same items that normally are prepared in a conventional oven or stove, including meats, casseroles, and fresh baked bread. Solar ovens can bake, boil, or steam all types of foods, with no danger of fire or burning of the food.
Why would you want to cook your food using solar energy? There are many reasons! Imagine using a source of green energy that is absolutely free, unlimited, and available on a daily basis. Using sunlight to cook your food requires no burning of wood or other fuel, thereby minimizing dependence on wood for fuel and reducing deforestation and the release of pollutants into the air. Because solar ovens operate outdoors, they do not contribute to unwanted heating inside your home.
In industrialized nations, home appliances such as refrigerators, ovens and stoves account for approximately 30% of the energy usage and 12% of greenhouse gas emissions. In developing countries, use of the (vanishing) supply of fuel wood is a significant contributor to greenhouse gas emissions. As the world's population increases and nonrenewable sources of energy for cooking continue to diminish, the need to identify and utilize clean, renewable energy sources grows ever more critical. The use of solar cookers is one potential piece of the puzzle available to tackle the significant issue of global warming, but one that is available to a large section of the world population and is relatively easy to implement.
Types of Solar Cookers
Although there are many different designs for solar ovens or cookers available, there are several basic principles that they utilize for heating strategy. An effective solar cooker typically will use some if not all of these design criteria:
- A method for concentrating the sunlight. A material or device such as a mirror, foil, or reflective material is used to channel concentrated sunlight and heat into a focused narrow area where the food is to be placed for cooking.
- A method for converting sunlight into heat. The most effective color for absorbing sunlight and converting it to heat is black. The cooker should be made of a conductive material with black to be most efficient at absorbing and transferring heat.
- Trapping and containing heat. It is critical to contain the heat which has been created by the absorbed sunlight within the solar oven, using some sort of clear solid barrier such as glass or plastic, which allows the sun's rays through but minimizes the loss of the created heat.
Using a Solar Cooker
Methods for preparing and cooking food will vary slightly with different solar oven designs, but in general the following principles will apply to most cookers:
- Food is sectioned into smaller pieces. To facilitate quicker cooking, items such as potatoes may be cut into smaller pieces.
- Solar cooker is placed in direct sunlight. Over the course of the cooking period, the oven location may need to be adjusted every hour or two depending on the sun's position to ensure it is in as direct a line as possible to the sun's rays.
- Optimum cooking performance occurs 2 hours before noon and 2 hours after noon in most climates.
- Cooking time will vary based on the climate conditions, time of day, size and quantity of food, and the specific oven design.
Useful Links regarding Solar Cooking and Ovens
For a list of great recipes for solar ovens, the solarovenchef.blogspot.com has an eclectic collection of recipes. The blogger has taken on the challenge of preparing all of his meals with a solar oven for an entire year, and it is an interesting read with lots of good information and cooking tips.
If you choose to buy one of the many available solar ovens out there commercially, we recommend that you consider the sun oven, which can be found at www.sunoven.com.
More ready-made solar ovens are available from nonprofit organizations such as the Solar Oven Society or Solar Household Energy.